Veterans of the Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn (OEF/OIF/OND) era are a unique population facing unprecedented obstacles; over 30% struggle with polytrauma, often a combination of traumatic brain injury (TBI), post-traumatic stress disorder (PTSD), and psychological distress.1,2 The resulting physical and psychosocial disabilities contribute to poor reintegration, characterized by high unemployment,3,4 deeply internalized stigma,5,6 and poor health status.7,8 These disabilities are also significant contributors to food insecurity; being able to access/make use of food in sufficient quantities to meet one?s perceived nutritional needs.9 Research is nascent, but preliminary data suggest that over 25% of OEF/OIF/OND Veterans are food insecure.10 Historically viewed as an economic concern, food insecurity is now understood to be influenced by a range of psychosocial determinants.11,12 Specifically, in the context of rehabilitation and recovery, there is an emerging understanding of nutrition as a multifactorial concept, one which encompasses the physical, psychosocial, and environmental factors that shape one?s relationship with food. Even as the International Classification of Functioning (ICF) prioritizes physical functions, (e.g. self-feeding), researchers have called for rehabilitation services to expand their approach beyond physical mobility or dexterity13,14 Nevertheless, the constructs that comprise food security, heretofore termed ?nutritional functioning?, have yet to be operationalized or systematically measured. The VHA?s Polytrauma System of Care provides rehabilitation services to thousands of Veterans.15 In addition, since 2014, the Integrative Health Coordinating Center has led the implementation of the Whole Health model of care,16 which offers integrative health (IH) modalities for polytraumatic injuries.17 Importantly, within the Whole Health model, ?Food and Drink? are core elements. Given this, both IH and polytrauma settings are ideal locations for operationalizing and creating a measure of ?nutritional functioning,? one that can be used to evaluate injured Veterans? use of and access to food, identify ?gaps? in for intervention, and serve as an outcome for randomized clinical trials. To operationalize nutritional functioning in OEF/OIF/ONF Veterans with polytrauma, and to develop a measure which encapsulates this concept, and can be validated in clinical settings, I propose to: Aim 1: Conduct qualitative interviews to further operationalize the components of nutritional functioning in OEF/OIF/OND Veterans with a history of polytrauma. Use the ICF framework to assess potential additional components, and associated barriers/facilitators to nutritional functioning. Interview VHA providers to assess perceptions regarding nutritional functioning. Aim 2: Develop and pilot a measure of nutritional functioning using components operationalized in Aim 1. Use expert panel input to evaluate content validity and clinical utility, and pilot the measure in a sample of OEF/OIF/OND Veterans with polytrauma. Combine exploratory factor and Rasch model analyses to evaluate dimensionality, scale appropriateness, and item level characteristics to inform measure refinements. Aim 3: Conduct a validation study of the refined measure of nutritional functioning in OEF/OIF/OND Veterans with and without polytrauma enrolled in IH and/or polytrauma rehabilitation services. Evaluate psychometric properties - reliability, validity (construct, known-groups and convergent validity) and Rasch measurement statistics to refine the measure further, and to develop it for future use as an outcome measure of nutritional functioning among those with polytrauma. This proposal addresses the RR&D goal of maximizing functional recovery by focusing on applied physical rehabilitation and psychological recovery. I will accomplish the proposed aims by seeking training in nutritional methods in interdisciplinary settings, measure development, and intervention design.